In a long term evolution (LTE) system, a user equipment (UE) performs an individual random access procedure attempt at a time, an initiates another random access procedure to again attempt to access when it is determined that this random access procedure attempt fails.
In a contention-based random access procedure, the UE randomly selects a preamble to transmit on a physical random access channel (PRACH). In non-contention-based random access procedure, a base station indicates the UE to use a preamble, and indicates the UE to use a specific PRACH time-frequency resource or indicates the UE to autonomously select a time-frequency resource.
It should be noted that the above description of the background is merely provided for clear and complete explanation of this disclosure and for easy understanding by those skilled in the art. It should not be understood that the above technical solution is known to those skilled in the art as it is described in the background of this disclosure.